铈含量对晶界扩散Nd-Ce-Fe-B磁体微观结构和性能的影响  

Microstructure and Magnetic Properties of Grain Boundary Diffused Nd-Ce-Fe-B Magnets with Different Cerium Contents

作　　者：宋瑞芳 张晓东 赵航[1] 冯海波[1] Song Ruifang;Zhang Xiaodong;Zhao Hang;Feng Haibo(Division of Functional Materials,Central Iron&Steel Research Institute,Beijing 100081,China;Shanghai Institute of Space Propulsion,Shanghai 201112,China)

机构地区：[1]钢铁研究总院功能材料研究所,北京100081 [2]上海空间推进研究所,上海201112

出　　处：《中国稀土学报》2024年第4期698-704,I0003,共8页Journal of the Chinese Society of Rare Earths

基　　金：国家重点研发计划项目(2021YFB3503002,2022YFB3503303)资助。

摘　　要：采用储量丰富的Ce元素部分替代Nd-Fe-B磁体中的Nd,以实现Ce稀土的高质化利用,是近年来稀土永磁领域的研究热点。本工作以Tb-Al-Ga合金为扩散源,研究了Ce含量及扩散工艺对晶界扩散Nd-Ce-Fe-B磁体微观结构和磁性能的影响。Ce含量较低的晶界扩散磁体中,Tb元素在主相晶粒外侧,形成高磁晶各向异性场的壳层结构,网状分布的Al元素作为非磁性相包裹主相晶粒,隔绝主相晶粒之间的交换耦合,使磁体矫顽力增加。Ce含量较高的晶界扩散磁体中,形成的富Tb壳层较厚,Al元素扩散进入主相晶粒内部,导致剩磁降低,隔绝主相晶粒交换耦合作用降低,矫顽力增量较小。The Ce elements with high-abundance partially replacing Nd in the Nd-Fe-B magnets can achieve high quality utilization of Ce elements,which is a hot research topic in the field of rare earth permanent magnets.Effects of grain boundary diffusion process and Ce content on the microstructure and magnetic properties of grain boundary diffused(GBD)Nd-Ce-Fe-B magnets were investigated using Tb-Al-Ga alloy as the diffusion source.It is shown that in the grain boundary diffused magnets with lower Ce content,Tb elements mainly form shell structure with high magneto-crystalline anisotropy field surrounding main phase grains,and Al elements wrap the main phase grains as non-magnetic phase,isolating exchange coupling between adjacent main phase grains.Therefore,the coercivity of the grain boundary diffused magnets increases substantially.In the grain boundary diffused magnets with higher Ce content,the thickness of Tb-rich shell is increasing.Al elements diffuse into the main phase grains resulting in remanence in decreasing and can not form non-magnetic phase to isolate the main phase grains leading to the decrease of coercivity.

关 键 词：烧结磁体 CE 晶界扩散 矫顽力 核壳结构 

分 类 号：TM273[一般工业技术—材料科学与工程] TG146[电气工程—电工理论与新技术]